I have a Java program, which launches a app, but before starting, it checks for the version.txt file, and if it doesn't exist, or there is a newer version available off my site, it downloads it. Well, not quite. I've got the part that checks for updates, and file existence, but not the updating part. I'm hoping I could make a launcher similar to the Minecraft game updater. So, I'll check for newer versions, and if one is available, it downloads the required files, and with a progress bar.